Polyacrylonitrile (PAN) nanofiber webs containing titanium dioxide were prepare via electrospin- ning. Either dimethyl formamide (DMF) or amount prepared employed its mixture with small of water and non-solvent water in to prepare 5 PAN/DMF or PAN/DMF/H20 solution, respectively. Introducing 20 solution was attempted to induce phase separation, which may lead to formation of porous structure on nanofibers surface. Different amounts of to wtx) were added Fl(H20) solutions and then electrospun webs. From SEM, possessed rough surfaces and had averaged diameters in ranges of 170-430 nm., showing tendency to increase with amount of Tio2 and water. Porous structure on fiber surfaces was not clearly observed, which was suspected to be due to insufficient amount of water employed. Less homogeneity in polymer solution due to presence of Tio2 disfavored increasing water content higher than 5%w/w. EDS data confirmed presence of Tioz in electrospun webs. From photocatalysis evaluation, webs containing 2 and 3 wtx Tio2 showed good photocatalytic activity such that 80 percent of 10 ppm. methylene blue degraded in 24 hours. Slight increase in photocatalytic activity was observed in webs obtained from pan/dmf/h2o